Self-centering roll



United States Patent U.S. Cl. 74241 11 Claims ABSTRACT OF THE DISCLOSURE A roll for centering strip including a shaft supporting two end strip supporting sections with a central strip supporting section therebetween. Each strip supporting section includes a plurality of spaced apart longitudinally extending radial webs secured to the shaft and a strip supporting surface at the outer end of each web with a space between the supporting surfaces.

This invention relates to a self-centering roll and more particularly to such a roll for use with wide, short belts and wide strip. Lorig Patent No. 2,817,940 dated Dec. 31, 1957, shows rolls for this purpose and the present roll is an improvement On the roll shown in FIGURE 3 of the patent. When handling certain materials, such as ore and food, or when operating a belt in dirty atmos pheres of various types, material will accumulate on the under side of the belt. When using any of the rolls of the Lorig patent it is extremely difficult to remove the accumulated material. Also, the dirt tends to work in between the parts of the roll and accumulate where it cannot be removed readily. This causes wear on the parts and, in the case of food processing, may result in the health inspectors requiring that the roll be dis-assembled and cleaned before continuing its use.

It is therefore an object of our invention to provide a self-centering roll which has no relatively moving parts and which can be readily cleaned without dismantling.

Another object is to provide such a roll which, when used with a belt, will autimatically remove most of the material that accumulates on the under side of the belt.

These and other objects will be more apparent after referring to the following specification and attached drawings, in which:

FIGURE 1 is a schematic end view of the roll of our invention in use in a belt conveyor;

FIGURE 2 is an enlarged sectional view of the roll of our invention; and

FIGURE 3 is a View taken on the line III-III of FIGURE 2.

Referring more particularly to the drawings, reference numeral 1 indicates the self-centering roll of our invention. Roll 1 has a shaft 2 which includes a cylindrical center portion 4 of maximum diameter, journal portions 6 at each end, an end portion 8 adjacent each journal portion having a diameter slightly less than that of the center portion, and a tapered portion 10 extending between center portion 4 and each portion 8. Each tapered portion 10 has a maximum diameter adjacent the center portion 4 and a minimum diameter adjacent the end portion 8. The taper of portion 10 is selected to give a uniform bending stress under load throughout its length. A sleeve 12 is welded to portion 4 and a sleeve 14 to each portion 8. A plurality of T-shaped segments 16, each having a web 18 and strip supporting head 20 are welded to each sleeve 14 in spaced apart relationship. The web 18 taper longitudinally toward the transverse center of the roll and are connected by a ring 22. The webs 18 are also connected at the outer end of the roll by a ring 24. Thus there are two unitary strip supporting roll end sections 26, each of which has a plurality of openings 28 from the work supporting surface to the interior of the roll and end openings 30.

A plurality of T-segrnents 32 each having a web 34 and a strip supporting head 36 are welded to the center sleeve 12 in alignment with T-segments 16. The webs 34 taper longitudinally away from the transverse center of the roll and are connected at each free end by rings 38. Thus a unitary strip supporting roll section 40 is provided at the center of the roll.

The rings 22, 24 and 38 may be omitted depending upon load requirements. The segments 16 and 32 may be other than T-shaped. For example, the heads 20 and 36 may be omitted or a round bar provided in place thereof. However, it is preferred that the outer strip supporting surface be on a circular are having its center at the roll axis. The length of portion 10 with respect to portions 4 and 8 is preferably such that the deflection of the sections 26 and 40 under load is the same at their adjacent ends so that the inner end of each section 26 would abut the adjacent end of center section 40 at a single point if enough load were applied. However, the clearance between the sections is so selected that under the designd load the sections will not abut.

It will be understood that the roll operates in essentially the same manner as the roll of the Lorig patent.

When the strip is an endless belt B as shown in FIG- URE 1 of the drawings it is preferred to use a narrow-' bodied roll 42 in combination with the self-centering roll 1. The narrow-bodied roll 42 may be constructed in the same manner as in the Lorig patent, but it is preferred to have it constructed in the same general way as the roll 1. In the latter case the roll 42 includes a shaft 6' having an extension 6'E connected to a motor or other drive means (not shown). A plurality of spaced apart radial webs 18 are supported by shaft 6' with a strip supporting head 20' at the outer end of each web 18. The webs 18' are connected at each roll end by a ring 24'. Openings 28' are provided between heads 20' into the interior of the roll. End openings 30' are provided at each end of the roll. It will be seen that this construction is essentially the same as that of roll 1, except that each strip supporting surface extends the full length of the roll rather than being in three spaced apart aligned sections. In addition each head 20' has a central section 20C of maximum uniform diameter and less length than the width of the belt B with the strip supporting head tapering from said central section to a minimum diameter at each end. This combination provides better centering than does a selfcentering roll alone.

While one embodiment of our invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

We claim:

1. Apparatus for centering a strip comprising a first roll having a shaft, a first strip supporting section surrounding one said end of said shaft, a second strip supporting section surrounding the other end of said shaft, and a third strip supporting section surrounding said shaft between said first and second sections, each of said strip supporting sections including a plurality of spaced apart longitudinally extending radial webs supported on said shaft and a strip supporting surface at the outer end of each radial web with a space between said supporting surfaces, said shaft having a maximum diameter center portion, end portions of less diameter than the center portion, and a tapered portion between each end portion and center portion, said tapered portion having a maximum diameter adjacent the center portion and a minimum diameter adjacent the end portion.

2. Apparatus according to claim 1 in which each strip supporting section includes a ring connecting the webs thereof.

3. Apparatus according to claim 1 including a central sleeve surrounding and secured to the center portion of the shaft, the webs of said third strip supporting section being secured to said central sleeve, a sleeve surrounding and secured to each end portion of the shaft, the webs of said first and second strip supporting sections being secured to the adjacent end sleeve.

4. Apparatus according to'claim 3 in which said shaft is shaped to have under load a uniform bending stress throughout its length.

5. Apparatus according to claim 1 including a second roll spaced from said first roll, said second roll having a shaft, a plurality of spaced apart radial webs supported by said shaft and a strip supporting surface at the outer end of each radial web with a space between said supporting surfaces, each of said strip supporting surfaces of said second roll having a central section of maximum uniform diameter and less length than the Width of the strip with the strip supporting surfaces tapering from said central section to a minimum diameter at each end, said strip being a belt passing around both of said rolls.

6. Apparatus for centering a strip comprising a first roll having a shaft, a first strip supporting section surrounding one end of said shaft, a second strip supporting section surrounding the other end of said shaft, and a third strip supporting section surrounding said shaft between said first and second sections, each of said strip supporting sections including a plurality of spaced apart longitudinally extending radial Webs supported on said shaft and a strip supporting surfaces at the outer end of each radial Web with a space between said supporting surfaces, the radial Webs of said first and second strip supporting sections being connected to said shaft adjacent the outer end thereof and disconnected from said shaft and spaced therefrom at the end adjacent the third strip supporting surface, and the radial webs of said third strip supporting sections being connected to said shaft at the transverse center thereof and disconnected from said shaft and spaced therefrom at the ends adjacent the first and second strip supporting sections.

7. Apparatus according to claim 6 in which said shaft has a maximum diameter center portion, end portions of less diameter than the center portion, and a tapered portion between each end portion and center portion, said tapered portion having a maximum diameter adjacent the center portion and a minimum diameter adjacent the end portion.

8. Apparatus according to claim "6 in which each strip supporting section includes a ring connecting the webs thereof.

9. Apparatus according to claim 6 including a central sleeve surrounding and secured to the center portion of the shaft, the Webs of said third strip supporting section being secured to said central sleeve, a sleeve surrounding and secured to each end portion of the shaft, the webs of said first and second strip supporting sections being secured to the adjacent end sleeve.

10. Apparatus according to claim 9 in which said shaft is shaped to have under load a uniform bending stress throughout its length.

11. Apparatus according to claim 6 including a second roll spaced from said first roll, said second roll having a shaft, a plurality of spaced apart radial Webs supported by said shaft and a strip supporting surface at the outer end of each radial web with a space between said supporting surfaces, each of said strip supporting surfaces of said second roll having a central section of maximum uniform diameter and less length than the width of the strip with the strip supporting surfaces tapering from said cen tral section to a minimum diameter at each end, said strip being a belt passing around both of said rolls.

References Cited UNITED STATES PATENTS 2,817,940 12/1957 Lorig 226-192 2,935,880 5/1960 Doyer 74-241 3,055,229 9/1962 Mecham 74-230 3,220,272 11/1965 Beausoleil 74-2306 3,363,476 1/1968 Brown 74-2306 3,392,594 7/1968 Gorp 74-2306 JAMES A. WONG, Primary Examiner US Cl. X.R. 

